Subdomain pointing issue

Hi,

I have a main domain example.com.au and created 2 subdomains x.example.com.au and y.example.com.au. I have uploaded all its related files using filezilla under the location /public_html/x_example_com_au and /public_html/y_example_com_au. But while access the subdomain like x.example.com.au and y.example.com.au, it is showing the following error

"[color=var(--heading-color)]This site can’t be reached [/color]x.example.com.au’s server IP address could not be found. Search Google for x.example.com.au [color=var(--error-code-color)]ERR_NAME_NOT_RESOLVED [/color]"

Also I have added these domains in /etc/sentora/configs/apache/httpd.conf file like below. But still showing the above error. Please help to solve this issue and to show its files.

# DOMAIN: x.example.com.au
<virtualhost *:80>
ServerName x.example.com.au
ServerAdmin *************************
DocumentRoot "/var/sentora/hostdata/********/public_html/x_example_com_au"
php_admin_value open_basedir "/var/sentora/hostdata/********/public_html/x_example_com_au:/var/sentora/temp/"
php_admin_value suhosin.executor.func.blacklist "passthru, show_source, shell_exec, system, pcntl_exec, popen, pclose, proc_open, proc_nice, proc_terminate, proc_get_status, proc_close, leak, apache_child_terminate, posix_kill, posix_mkfifo, posix_setpgid, posix_setsid, posix_setuid, escapeshellcmd, escapeshellarg, exec"
ErrorLog "/var/sentora/logs/domains/********/x.example.com.au-error.log" 
CustomLog "/var/sentora/logs/domains/********/x.example.com.au-access.log" combined
CustomLog "/var/sentora/logs/domains/********/x.example.com.au-bandwidth.log" common
<Directory "/var/sentora/hostdata/********/public_html/x_example_com_au">
  Options +FollowSymLinks -Indexes
  AllowOverride All
  Require all granted
</Directory>
AddType application/x-httpd-php .php3 .php
ErrorDocument 403 /_errorpages/403.html
ErrorDocument 510 /_errorpages/510.html
ErrorDocument 404 /_errorpages/404.html
ErrorDocument 500 /_errorpages/500.html
DirectoryIndex index.html index.htm index.php index.asp index.aspx index.jsp index.jspa index.shtml index.shtm
# Custom Global Settings (if any exist)

# Custom VH settings (if any exist)

</virtualhost>
# END DOMAIN: x.example.com.au
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